Temperature and pressure integrated MEMS sensor packaging process

Abstract

The invention discloses a temperature and pressure integrated MEMS sensor packaging process, which comprises the following steps: (1) silicon microbead mixed fixing glue is dripped on a PCB through a die bonder, and the silicon microbead mixed fixing glue is formed by uniformly mixing elastic microbeads and silica gel, the bottom of the conditioning circuit chip is attached to the upper portion of the silicon bead mixed fixing glue through a suction method and pressed on the PCB, and the temperature compensation MEMS pressure chip is attached to the conditioning circuit chip through the same method; (2) high-temperature curing; (3) carrying out wire connection by a gold wire bonding technology; (4) coating glue for fixing the metal protection body; (5) installing a metal protection body; (6) baking at high temperature to form a semi-packaged product; and (7) soft waterproof glue is injected. According to the invention, the silicon sensor substrate and the bottom support can be effectively isolated, and uniform isolation height and elastic bonding are realized, so that the stress minimization of the sensor is achieved, and the authenticity of the original output of the MEMS pressure sensor is kept.

Description

technical field [0001] The invention belongs to the technical field of pressure sensors, and in particular relates to a temperature and pressure integrated MEMS sensor packaging process. Background technique [0002] At present, piezoresistive sensors on the market are based on the Wheatstone bridge. The cavity is etched on the semiconductor silicon wafer to form a diaphragm, and a pressure-sensitive bridge is made on the diaphragm. When the diaphragm is subjected to external pressure, it deforms. , produces a piezoelectric effect on the induction bridge, and this piezoelectric effect has a relatively linear output. In the prior art, the compensation circuit for the output linearity of the piezoelectric effect at different temperatures is lacking or the synchronization between the compensation circuit and the temperature acquisition signal of the Wheatstone bridge is poor, resulting in the accuracy and responsivity of the current MEMS pressure sensor at different temperature...

AI Technical Summary

Problems solved by technology

In the prior art, the compensation circuit for the output linearity of the piezoelectric effect at different temperatures is lacking or the synchronization between the compensation circuit and the temperature acquisition signal of the Wheatstone bridge is poor, which leads to the accuracy and responsivity of the current MEMS pressure sensor at different temperatures. out of sync problem

In addition, when the silicon sensor substrate is isolated from the bottom support, the isolation height is inconsistent, the error is large, and the elasticity of the bonding is small, which causes the sensor to be affected by deformation, resulting in insufficient accuracy of the MEMS pressure sensor.

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